Improvements for Finding Impossible Differentials of Block Cipher Structures

Algorithm 1

Function UpdateMatrix.

// Update the augmented matrix    according to the variable vector  

(1) the size of ;

(2) for    to    do

(3) ;

(4) if    is    then

(5) Every element of the th column of is set to .

(6) else if    is not “?” and   is not “”   then

(7) the number of rows of ;

(8) for    to    do

(9) if    is    then

(10) ;

(11) ;

(12) end

(13) end

(14) end

(15) end